IT was a tale of two penalties – the stark contrast between them summing up the difference between these two bitter rivals’ campaigns.

Cristiano Ronaldo’s spot-kick, which proved the difference between the sides at Eastlands on Saturday, was confident, audacious – arrogant even – and its class showed why Manchester United are champions.

After Ronaldo was chopped down in the box by Michael Ball in the 32nd minute, the Portuguese firebrand brazenly stuttered his run-up to the spot, sending City keeper Andreas Isaksson the wrong way to give United the one-goal cushion which was enough to win Sir Alex Ferguson’s side the Manchester derby – and ultimately the Premiership title.

Darius Vassell’s late chance to equalise, on the other hand, couldn’t have been more different, and marked out why City will finish with the worst home goalscoring record since the Premiership began.

Whereas Ronaldo had looked convinced he wouldn’t miss from 12 yards, Vassell stepped up to the spot wearing the worried look of a man fearing he couldn’t hit the target in front of 47,000 supercharged supporters.

Edwin van der Sar was booked for the delaying tactics which no doubt deepened Vassell’s lack of confidence, the goalkeeper refusing to stand on his line and coming out to complain to referee Rob Styles that Vassell hadn’t placed the ball properly on the spot.

But the Dutchman will no doubt gladly take the yellow card after the winger’s kick went straight down the middle and rebounded from the goalkeeper’s outstretched leg with 11 minutes left.

His save denied City a draw, but even that result would still see United crowned champions after title rivals Chelsea could only draw 1-1 with Arsenal at the Emirates Stadium yesterday.

That miss signified the end of City as a force in the game, and it also gave a fateful symmetry to a fascinating contest which had rumbled furiously since the opening exchanges.

That contest was not the game itself, but a running battle between Ronaldo and City left-back Ball, who – despite a violent stamp on the United midfielder for which he should have been off the pitch and will no doubt receive a three-match ban – was the home side’s best player on the day.

The former Everton ace largely took the slippery Iberian trickster out of the game, but so many times this season Ronaldo – named player of the year by both players and pundits – has needed just one chance to lift his side on to the next level in their charge to the title.

And so it proved here as the Red Devils midfielder mercilessly leapt on the opportunity to hand out the ultimate punishment to his blue-shirted nemesis to score the winner with his 17th league goal of the season.

The duel should never have been allowed to develop. Just two minutes into the game, Ball scarred Ronaldo with a needless and vicious stamp on his stomach while the winger lay on the ground following a double challenge from the left-back and City midfielder Michael Johnson.

Ball’s attack was clearly intended to show a tired Ronaldo he was not going to be given the freedom of the pitch so often won by the winger in the Premiership this season.

But the City man’s crucial mistake then came when Alan Smith – back in the side after missing the midweek Champions League elimination by AC Milan – showed great vision to pick out Ronaldo with a cross-field ball into City’s 18-yard area.

Ronaldo charged at the left-back, befuddling him with a furious flurry of stepovers then crashing to the ground to win the penalty after his right foot was caught by Ball’s outstretched left.

The look on Ronaldo’s face as he stood and walked back to the spot had goal written all over it.

But Ball must have thought he had his revenge deep in the second half when – after United’s easy domination had forced City into a third tactical change of formation – the home side finally began to make some pressure tell on their visitors.

Ball charged into the United box, diving to the ground as right-back Wes Brown tried to step away from the challenge, convincing Styles to point to the spot for the second time.

Same end, different ending.

After the game Ferguson again laid into the Premier League for arranging a crucial lunch-time kick-off just over 48 hours after his players arrived back dejected from Milan in the early hours of Thursday morning.

But the Red Devils boss also praised his side for finding the fight and courage to notch another victory and extend their lead over Chelsea to eight points.

The fact is that once Ronaldo had put his team ahead, United had the relatively easy afternoon they needed – especially with what might have been a crucial decider against Chelsea looming at Stamford Bridge on Wednesday.

Fortunately for the Red Devils they didn’t need to exhaust themselves by tapping too hard at a robust City defence which never looked like it was going to be breached a second time.

For the first half-hour, spurred on by a pulsating, electric atmosphere only ever found at Eastlands when United are the visitors, City tried to rough up their visitors with a high-tempo game intended to stop their derby rivals from playing their usual fluid football.

But the folly of City’s tactics and formation was soon exposed, as United’s first-choice centre-back pairing of Rio Ferdinand and Nemanja Vidic – back together for the first time since March 31 – easily snuffed out the solitary threat of lone striker Emile Mpenza.

United’s containment job soon made City tire, allowing Ryan Giggs, Michael Carrick and the imperious Paul Scholes to pull the strings in the middle. Scholes dictated the tempo against an inexperienced City centre-pairing of Stephen Ireland and Johnson, the latter of whom was in for Joey Barton after the Everton target was last week suspended by the club for hospitalising team-mate Ousmane Dabo.

Not that United didn’t have their chances in the first half. Styles had already blown for an infringement by Vidic when the Serbian defender went close with a header, while on 22 minutes Ferdinand’s header rattled the bar after he leapt onto Ronaldo’s flick-on from a Giggs cross.

At the other end, Mpenza forced Van der Sar to dive down to his 15-yard volley, while DaMarcus Beasley’s shot from outside the box was comfortably gathered by the United keeper.

In the second half, Scholes shot straight at Isaksson from 25 yards after Ronaldo squared a free-kick to his midfield team-mate, while Mpenza’s header sailed just over the United crossbar.

City manager Stuart Pearce admitted afterwards that City’s problem all season had been the lack of a cutting edge up front – a weakness glaringly apparent as they failed to break a scoring hoodoo that has seen them goal-less in their seven home league games since New Year.

The look on Pearce’s face on the final whistle was that of a man who could well be spending his summer looking for another job.

And after the old enemy Arsenal did Ferguson’s side a favour yesterday, it’s one down, one to go for United in the quest for the double.